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Sand bodies in distributary channels and mouth bars of shallow water deltas are often distributed in continuous sheets， making it difficult to accurately classify the single sand body， limiting the accurate prediction of remaining oil distribution and restricting the further enhanced oil recovery （EOR）. Based on core， well logging， and other data， the characteristics of the sedimentary architectures of single sand bodies in shallow water deltas in the 1st Submember of the 2nd Member of the Eocene Shahejie Formation （Es21） and the 2nd Submember of 2nd Member of the Eocene Shahejie Formation （Es22） in Shenger District of Shengtuo Oilfield， Dongying Sag were systematically analyzed by using dense well pattern and interwell tracer data. The results show that shallow water delta deposits are developed in Es21 and Es22 in Shenger District of Shengtuo Oilfield， Dongying Sag， including plain subfacies and front subfacies of shallow water deltas. In addition， microfacies such as distributary channels， overbanks， mouth bars， and beach bars are developed. The sand bodies of shallow water deltas were divided into four architecture units （Levels 5-8）， and the single sand bodies in this study belong to the level-8 architecture unit. Six types of lateral contact patterns between single sand bodies were identified by comprehensively using dense well pattern and interwell tracer data： channel-overbank-channel splicing type， channel-channel cutting and stacking type， beach bar-beach bar splicing type， mouth bar-mouth bar splicing type， channel on dam cutting mouth bar type， and mudstone separating type. Interwell tracer data show that the sand body has the best connectivity in the channel on dam cutting mouth bar type， followed by channel-channel cutting and stacking type， mouth bar-mouth bar splicing type， and beach bar-beach bar splicing type. The worst connectivity is from the channel-overbank-channel splicing type. Finally， the sedimentary architecture models of single sand bodies in shallow water deltas in the study area were established. The microfacies type of the shallow water delta plain is mainly a distributary channel. The contact patterns between sand bodies in a single distributary channel mainly include lateral incising and overlapping， lateral contact with sand bodies on an overbank， vertical superposition， and oblique superposition. The microfacies types of sand bodies in the shallow water delta front are distributary channels， mouth bars， and beach bars. The contact patterns between sand bodies in a single mouth bar include vertical superposition， lateral splicing， oblique superposition， and mudstone separation. Two types of lateral splicing and vertical superposition exist between sand bodies in a single beach bar.

The conformational space of cis-1,2-cyclohexanediol, a model molecule for cyclic vicinal diols, was investigated using rotational spectroscopy and density functional theory calculations. Four low energy conformers within an energy window of 5 kJ mol−1 were identified computationally. A rotational spectrum of jet-cooled cis-1,2-cyclohexanediol was recorded with a chirped pulse Fourier transform microwave spectrometer. Two sets of rotational transitions were observed and could be assigned to conformers of cis-1,2-cyclohexanediol. The non-observation of other low energy conformers was explained by conformational conversion barrier height calculations and results from experimental spectra recorded with different carrier gases. Eight isotopologues, including those with 13C and 18O, of the lowest energy conformer were observed, allowing the determination of the semi-experimental equilibrium structure, reSE. Interestingly, the structural analysis revealed that the C–O bond length of the intramolecular hydrogen-bond donor is shorter than that of the acceptor. This appears to be a general characteristic of vicinal diols and can be used as a novel hydrogen-bond marker in such compounds. [ABSTRACT FROM AUTHOR]

The rotational spectrum of a binary complex formed between furan and n-hexane was investigated using a chirped pulse Fourier transform microwave spectrometer in the range of 2–6 GHz. While furan has only one conformer, n-hexane exists in multiple conformations. The conformational landscape of the binary complex was systematically explored by using a semiempirical conformational search tool, namely CREST. The CREST conformational candidates were subjected to further geometry optimization and harmonic frequency calculations at the B3LYP-D3BJ/def2-TZVP level of theory, resulting in 34 minima within an energy window of 5 kJ mol−1. The three most stable furan⋯hexane minima all contain the most stable n-hexane conformer subunit and are separated by relatively low conformational conversion barriers. Additional calculations were carried out to support the conclusive identification of the global minimum structure responsible for the set of assigned rotational transitions. These include calculations at the B3LYP-D3BJ level with the aug-cc-pVTZ and 6-311++G(d,p) basis sets and the MP2/def2-TZVP level, as well as the single point energy calculations at the CCSD(T)-F12/cc-pVDZ level. Further non-covalent interaction and principal interacting orbital analyses show that the synergy of the πfuran → σ*hexane and σhexane → π*furan interactions plays an important role in stabilizing the observed furan–hexane conformer. [ABSTRACT FROM AUTHOR]

As a key branch of the cross-discipline biophotonics, phototherapy, including photodynamic therapy (PDT), and photothermal therapy (PTT), is promising in biomedicine and visible light-driving PDT has been applied to clinical treatment. However, extensive applications of phototherapy are limited by the hypoxic microenvironment, laser penetration depth, and potential complexity for combined PDT/PTT. Thus, NIR-responsive oxygen self-supply nanocomposites functionalized with photosensitizers for achieving simultaneous in-depth PDT/PTT are urgently required. Herein, a multifunctional platform has been fabricated by co-immobilizing monodispersed ultrasmall Pd nanoclusters and a photosensitizer 5,10,15,20-Tetrakis (4-Aminophenyl)-21H,23H Porphyrin (Thp) on the surface of Ti3C2Tx MXene nanosheets, generating the Pd-Thp-Ti3C2Tx nanocomposite. Material characterization demonstrated that Pd nanoclusters and Thp were well-distributed on the MXene surface while MXene maintained its photothermal conversion efficiency and broad absorption. In this nanoplatform, irradiated by the single 808 nm laser, Pd selectively catalyzed the decomposition of H2O2 to O2, and O2 was continuously supplied to Thp for enhanced NIR-driving PDT. The in vivo fluorescence and photothermal imaging demonstrated the pronounced accumulation of nanocomposites in the tumor site. Both in vitro and in vivo results clearly demonstrated the nanocomposite had good biocompatibility, and that the synergistic PTT and enhanced PDT made apoptosis of the tumor cell achievable. This work not only proves this Pd-Thp-Ti3C2Tx nanocomposite serves a promising solution for tumor hypoxia by inducing apoptosis of tumor cells with synergistic PTT and PDT, but also broadens the application of promising optical materials in biomedical field.

The 1 : 2 adduct of 1-phenyl-2,2,2-trifluoroethanol (PhTFE), a chiral fluoroalcohol, with two water molecules (PhTFE⋯2H2O) was investigated via chirped pulse Fourier-transform microwave (CP-FTMW) spectroscopy and theoretical calculations. A systematic search of the PhTFE⋯2H2O conformational landscape identified 38 stable minima at the B3LYP-D3BJ/def2-TZVPPD level of theory, 27 of which are within an energy window of 10 kJ mol−1 after applying zero-point energy corrections. Rotational spectra of a single PhTFE⋯2H2O conformer along with eight deuterated and three oxygen-18 isotopologues were assigned. Interestingly, the observed PhTFE⋯2H2O conformer contains PhTFE II, the second most stable monomer conformer, and the most stable PhTFE I dihydrate is ca. 4 kJ mol−1 higher in energy. In contrast, PhTFE I⋯H2O was identified experimentally and theoretically as the most stable 1 : 1 conformer. Furthermore, the observed dihydrate structure experiences large amplitude motions connecting three theoretical minima which differ only in which water oxygen lone pairs are involved in the hydrogen-bonds, i.e., the free OH pointing directions. Additionally, the ortho and para-H2O tunnelling splittings were detected and attributed to the interchange water hydrogen atoms which interact with the aromatic part of PhTFE but not for the water interacting with PhTFE hydroxy group. Extensive theoretical modelling was carried out to gain insight into the associated large amplitude motions including tunnelling, supported by the experimental isotopic and tunnelling splitting data. [ABSTRACT FROM AUTHOR]

AbstractDroplet impact and freezing on solid surfaces are ubiquitous in many natural and engineering processes. Simulating the impacting-freezing process of a droplet is still challenging because it involves the complex multiphase flow and the liquid-solid phase change. This paper establishes a three-dimensional lattice Boltzmann model that considers the effects of contact angle hysteresis and volume expansion to simulate this complex process under realistic conditions. We adopt an enhanced cascaded lattice Boltzmann method to calculate the flow field and a multiple-relaxation-time scheme to solve the liquid-solid phase change model. In addition, a new contact angle model based on the pseudopotential multiphase lattice Boltzmann model is proposed to mimic the contact angle hysteresis. The simulations of droplet impact and freezing on both hydrophobic and hydrophilic surfaces with different surface temperatures and Weber numbers are conducted, and the temporal droplet profile and dimensionless contact length agree well with the experiments, which effectively validates the accuracy and robustness of the present model. Finally, the effects of surface temperatures (0,−15,−30∘C) and Weber numbers (4.4, 19.2, 40.0, 71.1) on droplet dynamics are also examined. [ABSTRACT FROM AUTHOR]